Every year, millions to billions of waste tires need to be disposed. Waste tires are a greater disposal problem than most wastes, because they will not stay buried in landfills. Instead, due to their unique shape, tires tend to trap gases and float to the top of a landfill. Consequently, waste tires are stored in tire piles or dumped illegally. In addition to being unsightly, these tires are a breeding ground for pests, such as mosquitoes or rats. Tire piles are inherently a fire hazard due to a combination of a flammable substance of rubber and excess air being trapped in the tires. Also, oil released from melting rubber can pollute ground or surface waters. These hazards become increasingly significant due to the sheer number of tires to be disposed. One solution to the growing tire problem is to reduce the production of waste tires by purchasing higher mileage tires, purchasing retreaded or remanufactured tires, or performing regular tire maintenance. A second solution is to reuse or recycle waste tires. Crumb rubber, a tire-derived material, is currently being used in highway pavement, athletic track surfaces, playgrounds, landfill liners, compost bulking agents, various manufactured products, energy recovery and artificial reefs for aquatic life. The crumb rubber is produced by chopping up waste tires, cleaning the chopped up rubber and removing any metal particles.
For wastewater filtration, gravity down-flow granular filters are commonly used, whereby sand or anthracite is used as a filter media. One major problem with granular filters is that upon backwashing the particles of media, the larger particles settle at a greater rate than the smaller particles. This ultimately causes the top of the filter bed to hold the smallest particles and the bottom of the filter bed to hold the largest particles, as shown in FIG. 1. This is a problem because the small particles have a less spacing or porosity between particles and this spacing becomes clogged quickly and easily.
It is an object of the present invention to provide an improved filter by using a media for the filter made from waste tires.